[Perf] Linux/x64: 3 Improvements on 6/8/2026 9:51:08 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [ea282a9bba0c233ff6f6410c45b9ba44f738ac76](https://github.com/dotnet/runtime/commit/ea282a9bba0c233ff6f6410c45b9ba44f738ac76)
Compare | [a0757694597c6be2827e9030f690a2b0c262e4cd](https://github.com/dotnet/runtime/commit/a0757694597c6be2827e9030f690a2b0c262e4cd)
Diff | [Diff](https://github.com/dotnet/runtime/compare/ea282a9bba0c233ff6f6410c45b9ba44f738ac76...a0757694597c6be2827e9030f690a2b0c262e4cd)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Improvements in System.IO.Tests.Perf_File

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|

• [WriteAllBytes - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 18.02 μs | 15.25 μs | 0.85 | 0.16 | False | | |
|

• [WriteAllText - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 25.34 μs | 22.42 μs | 0.88 | 0.26 | False | | |

![graph]()
![graph]()
[Test Report]()

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

```cmd
git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.IO.Tests.Perf_File*'
```

### System.IO.Tests.Perf_File.WriteAllBytes(size: 16384)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.IO.Tests.Perf_File.WriteAllText(size: 10000)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [ea282a9bba0c233ff6f6410c45b9ba44f738ac76](https://github.com/dotnet/runtime/commit/ea282a9bba0c233ff6f6410c45b9ba44f738ac76)
Compare | [a0757694597c6be2827e9030f690a2b0c262e4cd](https://github.com/dotnet/runtime/commit/a0757694597c6be2827e9030f690a2b0c262e4cd)
Diff | [Diff](https://github.com/dotnet/runtime/compare/ea282a9bba0c233ff6f6410c45b9ba44f738ac76...a0757694597c6be2827e9030f690a2b0c262e4cd)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Improvements in System.IO.MemoryMappedFiles.Tests.Perf_MemoryMappedFile

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|

• [CreateNew - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 17.58 μs | 12.96 μs | 0.74 | 0.04 | False | | |

![graph]()
[Test Report]()

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

```cmd
git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.IO.MemoryMappedFiles.Tests.Perf_MemoryMappedFile*'
```

### System.IO.MemoryMappedFiles.Tests.Perf_MemoryMappedFile.CreateNew(capacity: 10000)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

Start with the benchmark sources src/benchmarks/micro/libraries/System.IO.FileSystem/Perf.File.cs and src/benchmarks/micro/libraries/System.IO.MemoryMappedFiles/Perf.MemoryMappedFile.cs. Run the documented benchmarks_ci.py commands, inspect the linked reports and compare the baseline with the test results. Done means determining whether these wasm performance improvements require a concrete runtime change.

Written by the indexing model from the issue text.